The increase was led by a 59 percent YoY increase in pre-foreclosure inventory.

Delinquent loans have been working their way through the pipeline after the National Mortgage Settlement was finalized last year.

"The settlement provided some closure regarding accepted foreclosure processing practices, and as a result lenders have been reviving more of these delinquent loans and pushing them into foreclosure over the past 12 months," said Daren Blomquist vice-president of RealtyTrac in a press release.

"Particularly in states where a lengthy court process has resulted in a bigger backlog of non-performing loans still in snooze mode."

Here are some details from the report:

26 states reported increases in foreclosure inventory. Of these, 19 states have the judicial foreclosure process.

Of the 24 states that saw a decline in foreclosure inventory, 19 were non-judicial states.

The market value of homes that are in foreclosure or are bank owned rose 14 percent on the year to $200 billion in the first quarter.

The biggest increases in foreclosure inventory by loan amount took place on the high and low end of the market. For loans amounts of $5 million and more, foreclosure inventory was up a whopping 126 percent, but accounted for less than 0.25 percent of overall inventory.

Foreclosure inventory is down 39 percent from its December 2010 peak of 2.2 million units.

Here's a chart that shows U.S. foreclosure inventory since October 2007: